Search results

This paper aims to establish the mathematical models for the water-lubricated thrust bearing with groove texture considering turbulence and cavitation and numerically analyze the influence of rotary speed, texture depth, groove number and groove width on the static performance of the bearing.

The turbulent Reynolds equation and the Jakobsson–Floberg–Olsson cavitation model are adopted for the analysis. The Payvar–Salant algorithm and Finite difference schemes are used to discretize the governing equations. To illustrate the influence of turbulence, the performance of the bearing predicted by the turbulent and laminar models are compared.

According to the results, the load capacity and the friction force calculated by the turbulent model are greater than those obtained by laminar model, and the deviation between them gradually increases with the increased rotary speed. So, the turbulent effect should be fully considered for high-speed water-lubricated bearing with surface texture. There exists a peak value for the load capacity of the water-lubricated thrust bearing in respect to the texture depth, the number of grooves and the groove width ratio, while the friction force varies slowly with those parameters. Well-designed groove texture can improve the performance of the water-lubricated thrust bearing.

This paper proposes a mathematical model considering turbulent and cavitation effect for water-lubricated thrust bearing with surface texture. This model can be complementary to conventional laminar model which is used to analyze the performance of textured bearing at low rotary speed.

Based on the random aggregate model of recycled aggregate concrete (RAC), this paper aims to focus on the effect of loading rate on the failure pattern and the macroscopic mechanical properties.

RAC is regarded as a five-phase inhomogeneous composite material at the mesoscopic level. The number and position of the aggregates are modeled by the Walraven formula and Monte–Carlo stochastic method, respectively. The RAC specimen is divided by the finite-element mesh to establish the dynamic base force element model. In this model, the element mechanical parameters of each material phase satisfy Weibull distribution. To simulate and analyze the dynamic mechanical behavior of RAC under axial tension, flexural tension and shear tension, the dynamic tensile modes of the double-notched specimens, the simply supported beam and the L specimens are modeled, respectively. In addition, the different concrete samples are numerically investigated under different loading rates.

The failure strength and failure pattern of RAC have strong rate-dependent characteristics because of the inhomogeneity and the inertial effect of the material.

The dynamic base force element method has been successfully applied to the study of recycled concrete.

Based on the base force element method, a two-dimensional random circle aggregate model with Monte Carlo principle is proposed to carry out research on softening curve in meso-level.

The meso-level structure of recycled concrete is considered as the five-phase materials composed of aggregate, old interfacial transition zone, old mortar, new interfacial transition zone and new mortar. A multi-polyline damage model is adopted to describe the nonlinear mechanical behavior of recycled concrete material. The destruction state of the element is determined by the first strength theory. The research studies on damage process of recycled concrete under the loading conditions of uniaxial tension were established using the base force element method.

The softening curves of recycled concrete are obtained, which are in good agreement with experiment results. Simulation results show that the macroscopic mechanical properties and failure mechanism can analyze more reasonably from mesoscopic structure. Besides that, it can be investigated from the numerical results of the size effect in recycled concrete through the mesoscopic heterogeneity. Furthermore, the form of aggregate distribution has influence on the crack path but little effect on the tensile strength of recycled concrete.

The results show that the base force element method has been successfully applied to the study of softening curve of recycled concrete under uniaxial tension.

This paper aims to propose the five-phase sphere equivalent model of recycled concrete, which can be used to deduce the theoretical formulas for the Poisson’s ratio and effective elastic modulus.

At a mesoscopic level, the equivalent model converts the interfacial layer, which consists of the new interfacial transition zone (ITZ), the old mortar and the old (ITZ), into a uniform equivalent medium. This paper deduces a strength expression for the interfacial transition zone at the microscopic level using the equivalent model and elastic theory. In addition, a new finite element method called the base force element method was used in this research.

Through numerical simulation, it was found that the mechanical property results from the five-phase sphere equivalent model were in good agreement with those of the random aggregate model. Furthermore, the proposed model agree on quite well with the available experimental data.

The equivalent model can eliminate the influence of the interfacial layer on the macroscopic mechanical properties, thereby improving the calculation accuracy and computational efficiency. The proposed model can also provide a suitable model for multi-scale calculations.

The purpose of this study is to reconcile the positive, non-significant and even negative effects of guanxi on firm performance from two aspects. First, it explores the linear and curvilinear relationships between guanxi and distinct performance dimensions. Second, it examines the moderating effects of both exchange-related behavioral risk (reflected by contract enforcement in this study) and market-related environmental risk (reflected by market turbulence in this study) on the above relationship.

Based on data for 206 samples collected from distributors of house furnishings, computers and their components, a moderated regression is used to test the hypotheses.

The empirical test generally supports the conceptual model and demonstrates three findings. First, guanxi has a linear, positive effect on financial performance and an inverted U-shaped effect on strategic performance. Second, contract enforcement decreases the effect of guanxi on financial performance and enhances its effect on strategic performance. Third, market turbulence enhances the effect of guanxi on financial performance and weakens its effect on strategic performance.

First, this study collects data only from China. Future studies should collect data from other emerging markets to allow for either model validation or cross-country comparisons. Second, the data come only from buyers, and suppliers’ viewpoints are not included. Third, in addition to contract enforcement and market turbulence, other important contingencies should be considered in the guanxi–performance link.

The results provide important implications for managers to manage guanxi in an emerging economy. Managers should be very clear about their primary goal (i.e. pursuing short-term financial revenue or long-term strategic targets); next, they should understand how to match guanxi with various levels of contract enforcement and market turbulence to achieve that goal.

First, prior research has documented guanxi’s role in channel relationships, but it has not achieved consistent conclusions. Second, although existing studies have analyzed the contingencies of guanxi at the firm level, market level and institutional level, another important contingency “the dyadic relationship condition” is rarely considered. Third, although the extant research has realized the value of guanxi contingent on various market conditions, conflicting views exist. This study contributes by addressing these issues.

This study aims to enhance our understanding of how advanced IT improves the efficiency of contract governance in mitigating partners' opportunistic behaviors in interfirm cooperation and the moderating effects of boundary spanners' personal relationships and cooperative orientation.

Contract governance is divided into two subdimensions: contract completeness and contract execution safeguards. Then, the hypotheses are examined using partial least squares–based structural equation modeling based on survey data collected from manufacturers in supply chain relationships.

The results first demonstrate that advanced IT can improve efficiency in both the design of complete contracts and the provision of contract execution safeguards. Second, the results also show that both the personal relationships between boundary spanners and the cooperative orientation of the firm have different moderating effects. Finally, contract execution safeguards are effective in mitigating partners' opportunistic behaviors, whereas contract completeness is not.

This study enriches the contract governance literature in two ways. First, it unveils how advanced IT improves the efficiency of contract governance and the effects of two contingent factors (i.e. personal relationships and cooperative orientation), thus extending the research on contract governance. Second, it reveals the different effects of contract completeness and contract execution safeguards on partners' opportunistic behaviors, thus deepening our understanding of the role of contracts in interfirm cooperation.

This aim of this study was to explore the experiences of stigmatization and coping mechanisms during pregnancy among pregnant women who are living with HIV in Thailand. The secondary objective was to determine factors contributing to stigma during motherhood among HIV-infected women as well as explore how they cope with the discrimination from society.

Qualitative data were collected using in-depth interviews to obtain different versions of stigmatized experience from 16 pregnant women living with HIV on stigmatization and coping mechanisms. There were 5 pregnant adolescents living with HIV and 11 adult pregnant women living with HIV. The content analysis was used to examine patterns of stigmatizations and attributed factors.

Personal stigma was found among pregnant women living with HIV regardless of age. HIV status disclosure was the crucial barrier of accessing to care for people experiencing stigmatizations. Personal stigma associated with higher HIV status was not disclosed. Interestingly, all teenage mothers who participated in this study disclosed their HIV-status to their family. People who have social support especially from family and significant others are found to be able to cope and get through the difficulties better than those who lack those social support.

This study yields outcomes similar to several other studies that have been conducted either in Thailand or other countries. This study found that family support was crucial in reducing HIV stigma. Furthermore, HIV-infected pregnant female adults were more afraid to disclose their HIV status to their husbands, other family members and their work colleagues.

The multiple performance measures in strategic performance measurement systems should be selected to represent a set of causally linked strategic drivers and outcomes. The pattern of results thus can provide information concerning the proper execution of the strategy (i.e., the performance evaluation role) and the strength of the cause-and-effect linkages assumed by the strategy (i.e., the strategy evaluation role). Unfortunately, managers’ tendency to re-evaluate the strategy when performance falls short of target is low in practice. Possible explanations include motivational and cognitive biases. We experimentally examine two decision aids, an attribution aid, and a decomposition aid, designed to help managers ease these challenges. Study 1 shows the decision aids, individually and in combination, increase managers’ tendency to re-examine a problematic strategy. Study 2 demonstrates the effectiveness of the two decision aids, when used together, under a different pattern of results and among a sample of more experienced managers.

Female students comprise a significant number of the accounting student population at four-year institutions. Likewise, a significant number of students have chosen to enroll and earn associate degrees at a community college, and subsequently transfer to a four-year college or university. According to the National Center for Education Statistics, more than half of the students enrolled in two-year institutions were female. Moreover, 57% of college students in the United States are females. This study provides empirical evidence on the interaction between gender and transfer versus native accounting students in their academic performance during and after shock periods. According to the literature, the shock period includes two semesters after a two-year college student transfers to a four-year college. The results of this study indicate that female and male transfer students do not perform equally in their accounting courses compared to their native counterparts, that is, male transfer students in accounting performed worse than female transfer students and native students (male and female) both during and after the “shock” period. These findings may have practical implications for administrators and accounting departments since male transfer students appear to need more assistance to absorb transfer shock when they join four-year colleges and possibly even after their first year at the four-year institution.

The purpose of this study is to explore the relationships between shared leadership, psychological contract, felt obligation and employees’ creative deviance as well as to investigate the mediating role of psychological contract and the moderating role of felt obligation in these relationships.

This study used convenience sampling to obtain longitudinal data collected (interval of one week) from 348 frontline hotel employees. The SPSS Process Model 5 was used to test the moderated mediation model.

The results indicated that shared leadership has a significant positive impact on both employee creative deviance and psychological contract and psychological contract positively influences creative deviance. The results confirmed that the psychological contract mediated the relationship between shared leadership and employee creative deviance. The study also highlighted the moderating role of felt obligation on the relationship between shared leadership and employee creative deviance.

This study contributes to the literature on shared leadership, psychological contract, felt obligation and creative deviance by providing empirical evidence of the mediating and moderating effects of psychological contract and felt obligation on the relationship between shared leadership and employee creative deviance. The findings offer practical insights into how organizations can leverage shared leadership to enhance employee creative deviance through psychological contract and felt obligation.